Establishment of a new method for screening of CBFB-MYH11 fusion gene in acute myeloid leukemia and its value in clinical use / 中国实验血液学杂志

This study was purposed to establish new method for detecting CBFB-MYH11 fusion gene in acute myeloid leukemia (AML) and to evaluate its value in clinical use. All fusion types of reported CBFB-MYH11 fusion gene were defined by search of references and databank, then the primers and probes were designed on this basis, and 3 positive plasmids and negative cell line as control were established. GUSB gene was also amplified as an internal reference. The primer/probe sets were tested with 3 positive plasmids and HL-60 cDNA using quantitative real-time PCR (qPCR) assays, which were then combined as a multiplex qPCR for simultaneous detection of CBFB-MYH11 and GUSB. After optimization, the multiplex qPCR assay demonstrated both high sensitivity (10 copies for all the 3 plasmids) and high specificity. Finally, the multiplex qPCR assay was clinically evaluated with 58 AML patients, and 4 CBFB-MYH11-positive cases (6.9%) were detected, involving A type (3 cases) and J type (1 case). By comparison, the multiplex qPCR assay showed results concordant with sequencing results, and detected one case that was missed by cytogenetic analysis. It is concluded that a novel qPCR method for screening of CBFB-MYH11 fusion gene in AML is established. This method is fast, comprehensive, sensitive, specific, reliable, and should consider to be a robust tool for identification and management of AML patients with CBFB-MYH11 fusion gene.

Clinical Utility of Fluorescence in-situ Hybridization Profile Test in Detecting Genetic Aberrations in Acute Leukemia / 대한진단검사의학회지

BACKGROUND: Cytogenetic abnormalities are one of the most reliable prognostic factors in acute leukemia. Combination of conventional chromosome analysis (CCA) and FISH provides higher sensitivity in detecting these genetic abnormalities, and it is effective to apply several FISH probes as a profile test. The objective of this study was to investigate the utility of FISH profile analyses in the initial diagnosis of acute leukemia. METHODS: Two hundred and forty one de novo acute leukemia patients diagnosed from January, 2002 to November, 2007 were included. For acute lymphoblastic leukemia profile test, FISH probes for BCR/ABL, TEL/AML1, MLL gene rearrangement and CDKN2A deletion were used. For acute myeloid leukemia profile test, probes for AML1/ETO, MLL and CBFbeta gene rearrangement were used. The results of CCA and FISH profile tests were collected, and the positive rates were compared. RESULTS: ALL FISH profile tests revealed additional genetic aberrations not detected by chromosome analysis in 48.6% (67/138) of cases, including those with normal karyotypes or no mitotic cells (37%, 51/138). Among these 51 cases, TEL/AML1 abnormalities were detected in 44.3%, followed by the abnormal CDKN2A signal (24.6%) and hyperdiploidy (18.0%). AML FISH profile tests revealed additional genetic abnormalities in 7.8% (8/103) of cases. CONCLUSIONS: FISH analysis as a profile test detected additional genetic aberrations in a significant proportion of acute leukemia, and was effective especially in detecting cryptic translocations, submicroscopic deletions and complex karyotypes. Our study supports the need to incorporate FISH profile test at initial work up in acute leukemia.